Improvement in wood-screws



W. BUURN.

Wood Screws. No. 138,784. Patente dMay13J873.

Inz/enZZm UNITED STATES PATENT QFFIOE.

WILLIAM BOURN,OF GENEVA, NEW YORK.

IMPROVEMENT IN WOOD-SCREWS.

Specification forming part of Letters Patent No. 138,784, dated May 13, 1873 application filed August 1, 1872.

To all whom it may concern:

Be it known that I, WILLIAM BOURN, of Geneva, in the county of Ontario and State of New York, have invented a certain Improvement in Wood-Screw Points, of which the following is a specification:

The object of my invention is to provide a I wood-screw that will cut a hole the size of the stem of the screw as it is being driven into the wood, either hard or soft, without any tendency to split the timber, as does the ordinary gimlet-pointed screw now in use; and its nature consists in making the screw with a bradawl point instead of a gimlet-point, such bradawl point having a circular cutting-edge projectin g beyond the threaded portion of the screw.

Figure 1 is an elevation of an ordinary woodscrew having my improved point. Fig. 2 is a similar view of the same, but showing one side or edge of the cutting-point.

The great advantages of the gimlet-pointed over the old-fashioned screw are well-known, yet it is quite as well understood that the gimlet-point acts as a wedge in penetrating the wood, only parting the grain, there being, therefore, a strong tendency to split the timber. This tendency I wholly obviate by providing the screw with a flattened or brad-awl point, as shown at a in the drawing, which point actually bores or cuts the hole for the reception of the stem as the screw is being turned in, the thread of the screw being pressed into the wood.

Of course all kinds and sizes of wood-screws may be made with this kind of point, whether they have slotted heads for a screw-driver or square heads for a wrench.

Repeated experiments with large and small screws provided with my improved points in various kinds of wood have clearly demonstrated that such screws can be used without any liability to split the timber. They can be inserted with far less labor, and, therefore, proportionally reducing the strain upon them and the liability to twist them off while they are being driven in.

What I claim as my invention, and desire to secure by Letters Patent, is-

As an improved article of manufacture, a wood-screw provided with a flattened point having a circular cutting-edge, as and for the purposes set forth.

WM. BOURN.

Witnesses:

JOHN PEARCE, PATRICK MCINTYRE. 

